Attachment for drills



Au v, 1928. 1,679,884

H. 'r. THOMAS ATTACHMENT FORYDRILLS w Filed Oct. 22, 1926 INVENTOR.

ATTORNEY.

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Patented Aug. 7, 1928. I v

UNlTED STATE PATENT orrlc.

HORACE THOMAS, 013 LANSING, MICHIGAN.

ATTACHMENT FOR DIS.

Application filed October 22, 1926. Serial R0. 149.47%,

y invention relates to an attachment for motor driven hand drills, and an object of my improvements is to provide a sim la and eficient attachment that shall adapt e drill to operates. reciprocating tool.

ii secure this object in the device illustrated in the accompanying drawing in which:

Figure l is a side elevation of an electric, or air, drill with an ap aratus embodyin my invention attached t ereto %igure 2 is a section on the line 11, II Figure l.

a, a, indicates a conventional dIlll, the spindle a of which is driven by "a small motor at a involving the rapid rotation of a considerable mass in a plane at right angles to the axis of the spindle.

a is thehandle and a, a cylindrical projection from the stationary portlon, or frame, of the drill in which projectlon 1s the bearing for the spindle a.

h is a casing adapted at b to fit over the projection a and be secured thereto as by a set screw b.

The casing b encloses the outer end of the spindle a...

b is an. enclosing head, or cover, for the b" is a cylindrical aperture through the cover I) and b isa similar aperture in the head of the casing 72 axially in line with the aperture b, These two apertures form bearlngs for a reciprocating rod 0- which extends from the casing h at lts forward end and is formed at this end, at at, to adapt it to have a reciprocating tool such as the saw shownin the drawing, attached thereto,

0 is a transverse slot cut in the upper portion of the rod a.

d is a sleeve fitting and secured upon the outer end oi the spindle a. e is a ring surrounding the sleeve d and immovably secured to said ring.

There is a second sleeve fixed on the spindle a and the rin e is clamped between the inclined opposite aces of the two sleeves by a nut on the outer end of said spindle, whereby the ring may be easily removed and replaced.

The plane of the ring a is not at angles to the axis of the sleeve 02 and spindie a but is considerably inclined thereto. Said ring is rovided with a ball race around its periphery. f is a second ring surrounding the ring e and provided with a right ball race around its interior surface. 9' indicates the balls enga g in said races in the rings a and 7 an securing said rings together concentric with each other.. The ring I engages at its lower portion in the slot 0 in the rod 0.

The operation of the above described dewoe is as follows:

A tool adapted to be operated b reciprocation is secured to the outer en of the rod c and the motor is set in motion revolvmg the spindle a which carries with 11; the sleeve d and ring e. The ring 0 acts throu h the balls g and ring 7" as a cam, or wo ble plate, upon the walls of the slot 0 to reclprocate the rod 0 and tool 0.

The apparatus described may be readily adplsted to drills of conventional construct1on and the whole apparatus may be fixed to a stationary support or may be carried to the work. 7

The inertia of the wliole tool and that of the rotating armature, or motor, holds the body of the tool stationary and throws the reciprocatory motion to thecutting tool.

What I claim is:

1. The combination of a portable apparatus of the kind described having a spindle and means for rotating the same, a part adapted to carry a tool and reciprocate in the direction of the axis of said spindle, a wobble-plate on said spindle, a ring surrounding said plate, a friction hearing between said ring and plate, said ring engaging" said part to reciprocate the same.

Q. The combination with a portable apparatus of the kind described having a spindle and means for rotating the same, a housing adapted to be removably secured to said apparatus with said spindle extendinz through its wall, a tool bearing part adapted to reciprocate in hearings in said housing in a direction parallel to said spindle and located at one side of said spindle. and a wobble-plate adapted to be removablv secured to said spind e with its hub passing over the same within said housing, and to engage said part to reciprocate the same.

lltlli lltl cicnt rotational momentum to substantially absorb the torques due to the momentum of g the reciprocating part.

4. The combination with a portable appa-. ratus of the kind described having a rotating part, of a part on said drill adapted to reciprocate in a line parallel to, and at one side of, the axis of said rotating part, and a cam on said spindle adapted to engage 10 said reciprocating part, said rotating part having sufiicient rotational momentum to substantially absorb the torques due to the momentum of the reciprocating part.

5. In an apparatus of the kind described, the spindle a), two sleeves adapted to be removably adjusted upon said spindle and having their adjacent end surfaces parallel and inclined to the axis of said spindle and a ring e between the adjacent ends of said sleeves for the purpose described and means for forcing said sleeves together to clamp said ring between the adjacent ends of said sleeves.

In testimony whereof, I sign this specification.

HORACE T. THOMAS. 

